(optionally 17-alkylated) 17-oxygenated 5alpha-androst-2-en-4-ones and intermediatesthereto



United States Patent 7 The present invention is concerned with novel 4-ketosteroids of the androstane series and, more particularly,

with (optionally 17-alkylated) 17-oxygenated Sa-EmdIOSl- 2-en-4-ones represented by the structural formula.

. IIH 0 2 wherein X is a carbonyl, ,B-hydroxymethylene, B-(lower alkanoyl)oxymethylene, or a-(lower alkyl)-,8-hydroxymethylene radical.

Those novel compounds can be obtained by processes utilizing the novel intermediates designated by the following structural formula CH3 CH3 Br-- Z g wherein X is as defined above and Z is a carbonyl or 5- hydroxymethylene radical.

In the foregoing structural representations, the lower alkyl radicals encompassed in the X substituent are exemplified by methyl, ethyl, isopropyl, secondary-butyl, tertiary-pentyl, hexyl, and heptyl, while the lower alkanoyl radicals designated therein are typified by acetyl, propionyl, butyryl, valeryl, caproyl, heptanoyl, and the branched-chain groups isomeric therewith, said radicals containing fewer than 8 carbon atoms. a

The 4-keto-A compounds of this invention display valuable pharmacological properties as evidenced by their hormonal and anti-hormonal activity. They are, for example, anabolic, androgenic, anti-estrogenic, and antifertility agents.

Starting materials suitable for use in the manufacture of the novel substances comprising the present invention are defined by the following structural formula CH3 CH3 substances are converted to the corresponding 3a,4,8- bromohydrins by reaction with aqueous hypobromous acid. That reagent is preferably prepared in situ, for example from a mixture of N-bromosuccinimide and aqueous perchloric acid. Oxidation of the 3a,4;3-bromohydrins thus obtained, typically with chromium trioxide in aqueous acid medium, affords the 4-keto derivatives corresponding. Dehydrobromination of the latter 3a-br0m0- 4-keto intermediates creates a doubly bonded unsaturated linkage at the 2,3-position, thus producing the instant 4- keto-A compounds. The foregoing processes are specifically illustrated by the reaction of 5ot-androst-3-en-l7fiol 17-acetate with N-bromosuccinimide in aqueous perchloric acid to yield 3a-br0mo-5u-androstane-4p,17,8-diol 17-acetate, oxidation pf that bromohydrin with chromium trioxide in aqueous acetic acid, resulting in 17B-acetoxy- 3a-bromo-5wandrostan-4-one, and dehydrobromination of the latter substance with a mixture of lithium chloride and lithium carbonate in dimethylformamide to produce the instant l7,8-acetoxy-5a-androst-2-en-4-one.

Hydrolysis of the instant 17,8-(lower alkanoyl)-oxy-5uandrost-2-en-4-ones, typically with aqueous potassium hydroxide in methanol, provides another method for the manufacture of the instant 17,8-hydroxy-5a-androst-2-en 4-one. The latter 17(3-01 can alternatively serve as the starting material for manufacture of the corresponding alkanoyl esters. Acylation with a lower alkanoic acid halide or anhydride in the presence of a suitable acid acceptor is a preferred procedure. In that manner, 17E- hydroxy-5u-androst-2-en-4-one is contacted with propionic anhydride and pyridine to yield the 17-propionate thereof.

The 17-alkylated compounds of this invention are conveniently obtained by conversion of the aforementioned 5a-androst-3-en-17-one to a 17oz-(1OW6I' alkyl)-5a-androst 3-en-17fl-o1 by reaction with a suitable alkyl organometallic reagent, and subsequent application of the aforementioned bromohydrination, oxidation, and dehydrobromination reactions to those intermediates. As a specific example, 5a-androse-3-en-l7-one is contacted with ethyl magnesium bromide in'ether solution, and the resulting adduct is hydrolyzed in aqueous ammonium chloride to produce l7oc-ethyl-5a-androst-3-en-1713-01.f Transformation of that substance to the instant l7a-ethyl-17fi-hydroxy- 5a-androst-2-en-4-one is effected by processes analogou to those detailed hereinbefore.

The following examples describe in detail certain of the compounds illustrative of the present invention and methods which have been devised for their manufacture. The invention, however, is not to be construed as limited thereby either in spirit or in scope since it will be apparent to those skilled in the art that many modifications both of materials and of methods may be practiced without departing from the purpose and intent of the disclosure. In the examples hereinafter detailed, temperatures are given in degrees centigrade C.) and quantities of materials in parts by weight unless otherwise noted.

Example 1 A solution of 2.5 parts of 5a-androst-3-en-17-one in 60 parts of dioxane, under nitrogen, is cooled by means of a water bath While 2 parts of N-bromosuccinimide, 1.7 parts of 60% aqueous perchloric acid, and 18 parts of water were added successively with stirring over a period of about 5 minutes. That reaction mixture is stirred at room temperature for about 4 hours, then is quenched by pouring into cold water containing 0.01 part of sodium thiosulfate. The resulting precipitate is iso lated by vacuum filtration, washed with water and dried O to afford 3a-bromo-4fi-hydroxy-5wandrostan-17-one, melt ing at about 226-228". It is characterized further by an optical rotation of +60 in chloroform and can be represented by the structural formula CH: H

1 fr HO Example 2 To a solution of 3 parts of 3a-bromo-4p3-hydroxy-5aandrostan-17-one in 120 parts of acetone, obtained by warming a mixture of those two components, is added dropwise, at room temperature, an aqueous solution, 8 N in chromium trioxide and 8 N in sulfuric acid, until an excess of the reagent is present as evidenced by the persistence of an orange color. The excess reagent is destroyed by the addition of a small quantity of isopropyl alcohol, and the preciptated inorganic salts are removed by filtration. The filtrate thus obtained is poured into a mixture of ice and Water, resulting in preciptation of the product which is washed on the filter with water and dried in air to yield 3a-bromo-5a-androstane-4,17-dione, melting at 145-146". It is characterized further by infrared absorption maxima at about 3.4, 5.72, and 5.80 microns and also by the structural formula Example 3 A mixture of 2.75 parts of 3a-bromo-5a-androstane- 4,17-dione, 1.6 parts of lithium chloride, one part of lithium carbonate, and 70 parts of dimethylformamide is heated at the reflux temperature for about 3 hours in an atmosphere of nitrogen. The reaction mixture is then cooled to room temperature and poured into water, and the resulting aqueous mixture is extracted with ether. Washing of that organic solution with dilute hydrochloric acid followed by drying over anhydrous postassium carbonate containing decolorizing carbon affords an organic solution, which is stripped of solvent by distillation at reduced pressure to afford the crude product. Recrystallization from acetone-hexane affords pure a-androst-2- ene-4,17-dione, melting at about l72l75 and displaying infrared absorption maxima at about 3.4, 5.73, 5.94, and 6.14 microns in addition to an ultraviolet absorption peak at about 227 millimicrons with a molecular extinction coefiicient of about 7200. This substance can be represented by the structural formula 0 OH: H

4 Example 4 To a solution of 16 parts by volume of 3 molar methyl magnesium bromide in 14 parts of ether is added dropwise, with stirring over a period of about 15 minutes, a solution of 0.8 part of 5ot-androst-3-en-17-one in 14 parts of ether. The reaction mixture is heated at the reflux temperature for about 16 hours, then is poured slowly into a mixture of ice and water containing 8 parts of ammonium chloride. The resulting aqueous mixture is extracted with ether, and the ether layer is separated, washed successively with dilute hydrochloric acid and 5% aqueous sodium bicarbonate, then dried over anhydrous potassium carbonate containing decolorizing carbon. Removal of the solvent by distillation affords a residue which is crystallized from aqueous methanol to yield 17a-methyl-5a-androst-3-en-17,8-01, characterized by a melting point of 1395-" and an optical rotation of +30 in chloroform.

Example 5 To a solution of 8 parts of 17a-methy1-5a-androst-3-en- -01 in 85 parts of dioxane, under nitrogen, is added with slight cooling a solution of 1.5 parts of 60% perchloric acid and 2.6 parts of N-bromosuccinimide in 30 parts of water. That reaction mixture is stirred at room temperature for about 4 hours, then is poured carefully into approximately 3000 parts of a mixture of ice and water. The precipitate which forms is collected by filtration, washed on the filter with water, then recrystallized from methanol to afford pure 30c-bIOI110-17a-11'16thYl-50tandrostane-4fi,l7, 3-diol, melting at about 182184 with decomposition. Infrared absorption maxima are observed at about 2.75 and 3.4 microns. The following illustration structurally represents this substance CH "CH3 Example 6 A solution of 1.05 parts of chromium trioxide in 15 parts of acetic acid is added dropwise over a period of about 15 minutes, with stirring and cooling, to a solution of 2.35 parts of 3ot-bromo-17a-methyI-Sa-androstane-4f3, l7/3-diol in 35 parts of acetic acid, and the reaction mixture thus obtained is stirred at room temperature for about 16 hours. At the end of that time, the solution is poured carefully into a mixture of ice and water, and the resulting precipitate is isolated by filtration, then washed with water and dried in air. Recrystallization of that crude product from aqueous methanol affords pure 3a bromo-l7fl-hydroxy-17u-methyl-5ot-androstan-4-one, melting at about 130.5-133 and characterized further by an optical rotation of 141 in chloroform. It can be represented by the following structural formula on3 LHCH:

and an optical rotation in chloroform of -4.5.

Example 7 To a solution of 10 parts of 3ot-bromo-l7fl-hydroxy- 17u-methyI-Sa-androstan-4-one in 250 parts of dimethylformamide is added successively 5.2 parts of lithium chloride and 3.5 parts of lithium carbonate, and that reaction mixture is heated at the reflux temperature for about 3 hours in an atmosphere of nitrogen, then is stored at room temperature for about 16 hours. At the end of that time, the reaction mixture is diluted by the addition of about 500 pants of water, and that aqueous mixture is extracted with ether. Successive washings of the ether extract with dilute hydrochloric acid, water, and 5% aqueous sodium bicarbonate followed by drying over anhydrous sodium sulfate containing decolorizing carbon and removal of the solvent by distillation at reduced pressure affords the crude product as a glass. That glassy substance is recrystallized from a mixture of acetone and hexane, thus affording pure 17,8-hydroxy-17a-methyl-5otandrost-2-en-4-one, which displays a melting point at about 132-136" and is characterized further by an ultraviolet absorption peak at about 225.5 millimicrons with.

a molecular extinction coefficient of about 7248. It can be represented by the following structural illustration H CH3 Example 8 A solution of par-ts of 5u-androst-3-en-l7 8-ol 17- acetate in 100 parts of dioxane is stirred in a nitrogen atmosphere while 4 parts of N-bromosuccinimide, 3.4 partsof 60% perchloric acid, and 35 parts of water are added successively over a period of about 5 minutes with cooling by means of a water bath. Stirring of the resulting reaction mixture is continued at room temperature for about 3 /2 hours, after which time it is poured into a mixture of ice and water containing 0.01 part of sodium thiosulfate. The precipitate which forms is collected by filtration, then is washed with water and dried in air to afford the crude product. Recrystallization from methanol affords pure 3a-bromo-5a-androstane-4fi,l7fl-diol l7- acetate, displaying a melting point at about 166-168 The following formula illustrates its structure 0 O ACHa Example 9 v To a solution of 3 parts of 3a-bromo-Sa-androstane- 4,8,l7/3-diol 17-acetate in 40 parts of acetic acid is added, at 0-5" with stirring over a period of about 30 minutes,

75, by infrared absorption peaks at about 2.75, 3.4, 5.95, and.

a solution of 1.3 parts of chromium trioxide in 24 parts of acetic acid containing 1.4 parts of water. Stirring of the resulting reaction mixture is continued at room temperature for about 16 hours, following which period of I time that mixture is poured carefully into a mixture of ice and water. The precipitate which results is collected by filtration, washed on the filter with Water, and dried in air. The crude product thus obtained is recrystallized from aqueous methanol to yield 17B-acetoxy-3a-brorno- 5a-androstan-4-one hemihydrate, melting at about Example 10 To a solution of 24 parts of 17B-acetoxy-3u-bromo-5w androstan-4-one in 600 parts of dimethylformamide is added 8.5 parts of lithium carbonate and 13 parts of lithium chloride, and that reaction mixture is heated at the reflux temperature for about 3 /2 hours, then is stored at room temperature for about 16 hours. Dilution with approximately 500 parts of water alfords an aqeous mixture which is extracted with ether. The aqueous layer is separated, acidified by means of dilute hydrochloric acid, then extracted with ether. The combined ether solutions are Washed successively with dilute hydrochloric acid, 5% aqueous sodium bicarbonate, and water, then dried over anhydrous sodium sulfate containing decolorizing carbon. Distillation of the solvent at reduced pressure affords an oily residue which solidifies on standing. That crude product is recrystallized from aqueous methanol to yield pure 17fi-acetoxy-5a-androst-2-en-4-one, melting at about l82184 and characterized further by an optical rotation of +7.5 in chloroform. It displays an ultraviolet absorption peak at about 226 millimicrons with a molecular extinction coefficient of about 7500 and can be represented by the following structural formula O COCHQ CH Example 11 To a solution of 8 parts of 17fi-acetoxy-5u-androst-Z-en- 4-one in 560 parts of methanol is added a solution of 20 parts of potassium hydroxide in 200 parts of water, and

the resulting reaction mixture is heated at the reflux temperature for about 30 minutes. Cooling to 0-5 followed by dilution with water results in precipitation of the desired product, which is collected by filtration and dried to afford 17p-hydroxy-5a-androst-2-en-4-one, char-.

acterized by a melting point of about -l60 and also 6.1 microns. Its structure is illustrated by the following representation H OH? I Example 1 2 A mixture of one part of 17/i-hydroxy-5a-androst-Z-en- 4-one, 13 parts of propionic anhydride, and 20 parts of pyridine is allowed to stand at room temperature for about 16 hours, then is poured carefully into approximately 200 parts of water. The aqueous mixture which results is extracted with ether, and the organic layer is separated, washed successively with water, dilute hydrochloric acid, and water, then dried over anhydrous sodium sulfate. Distillation of the solvent at reduced pressure affords a crystalline residue consisting of 17fi-propionoxy-Sa-androst-2-en-4-one, characterized by the structural formula OCOCHZCHQ Example 13 To 28 parts of a 3 molar solution of ethyl magnesium bromide in ether is added, over a period of about 10 minutes with stirring, a solution of 2 parts of Soc-androst- 3-en-17-one in 28 parts of ether. The resulting reaction mixture is heated at the reflux temperature for about 16 hours, then is poured into ice-cold saturated aqueous ammonium chloride, and the resulting aqueous mixture is extracted with ether. The ether solution is washed successively with water and 5% aqueous sodium bicarbonate, then is dried over anhydrous potassium carbonate containing decolorizing carbon. The solvent is distilled at reduced pressure to afford an oily residue which is recrystallized from aqueous methanol to yield l7a-ethyl- 5a-androst-3-en-17B-ol, characterized by infrared absorption maxima at about 2.75, 3.4, and 6.02 microns.

To a solution of 5 parts of 17ol-ethyl-5a-androst-3-en- 17fi-ol in 100 parts of dioxane is added over a period of about 5 minutes, with cooling by means of a water bath and stirring in a nitrogen atmosphere, a solution of 10 parts of N-bromosuccinimide and 3.4 parts of 60% aqueous perchloric acid in 35 parts of water. Stirring is continued at room temperature for about 4 hours, and the reaction mixture is then poured into water containing crushed ice. The precipitate which forms is collected by filtration, washed on the filter with water and dried in air. Recrystallization from methanol results in 30:- bromo-lh-ethyl 50c androstane-4B,17,8-diol, which exhibits characteristic infrared absorption peaks at about 2.75 and 3.4 microns.

Example 14 The oxidation of 2.44 parts of 3a-bromo-17a-ethyl-5aandrostane-4B,17/3-diol by the procedure described in Example 6 results in 3oL-blOlDO-170t-6lhYl-17fl-1I1YdIOXY-5ocandrostan-4-one.

8 Example 15 By substituting 10.37 parts of 3a-bromo-17a-ethyl-17fihydroxy-Sa-androstan-4-one and otherwise proceeding according to the processes described in Example 7, 17aethyl-l7,8-hydroxy-5a-androst-2-en-4-one is obtained. It is represented by the structural formula CH3 "or-non.

Example 16 The substitution of, 2.5 parts of 5a-androst-3-en-17/3-ol in the procedure described in Example 1 results in 3abromo-5a-androstane-4B,17/3-diol of the structural formula OH CH3 Example 17 Example 18 The oxidation of 3.1 parts of 3a-bromo-5a-androstane- 4fl,l7fi-diol 1 7-propionate by the processes of Example 9 results in 3a-bromo-l7,8-propionoxy-5a-androstan-4- one. It is represented by the structural formula O C O CI-I CH; CH3 I OH CH3 Example Dehydrobromination of parts of M lamine-1718- propionoxy-5a-androstan-4-one by the procedure described in Example 10 results in 17fi-propionoxy-5otandrost-2-en-4-one, identical with the product of Example \l 2. i

v v Example 21 The substitution of 2.75 parts of 3x-bromo-17[i-hydroxy-Sa-androstanl-one in the processes of Example 3 results in 17,8-hydroXy-5a-androst-2-en-4one, identical with the product of Example 11.

What is claimed is: 1. A compound of the formula Cl ls CH3 II E 0 wherein X is a member of the class of radicals consisting of carbonyl; fi-hyd-roxymethylen'e, fs-(lower alkanoyl) oxymethylene, and a-(lower alkyl)-,8-hydroxymethylene.

2. Su-audrost-Z-eneld7-dione.

3. 17fl-hydroXy-5oa-androst-2-en-4-one.

4. A compound of the formula OH CH3 -"(IOWBr alkyl) 5 17fi-hydroxy-17oc-methyl-5a-andro'st2-en-4-one. 6. A compound of the formula 0 C O r 1 C H3 I (10 er a1 ryl) O y 7. 17/3-acetoxy-5a-andr0st-2-en-4-one.--

' 8. Acompound of the formula wherein X is selected from the group of radicals consisting of carbonyl, fl-hydroxymethylene, fl-(loweralkanoyl) oxymethylene, and a-(lower alkyl)-B-hydroxymethylene, and Z is a member of the'class of radicals consisting of carbonyl and ,B-hydroxymethylene.

9. 3a-ibromo-4/3-hydroxy-5wandrostan-17-one.

10. 3owbromo-Sot-androstane-4fl7-dione.'

12. 30c bromo-17fl-hydroxy-l7tt-methyl-5ot-androstan- 4-one.

13. 3a-bromQ-Sa-androstanet-p,17fi-diol 17-acetate. 14. 17B-acetoXy-3m-hromo-5a-androstan-4-0ne.

No references cited. 7 

1. A COMPOUND OF THE FORMULA 4-(O=)-ANDROST-2-ENE WHEREIN C17=X WHEREIN X IS A MEMBER OF THE CLASS OF RADICALS CONSISTING OF CARBONYL, B-HYDROXYMETHYLENE, B-(LOWER ALKANOYL) OXYMETHYLENE, AND A-(LOWER ALKYL)-B-HYDROXYMETHYLENE. 